Touch panel and apparatus for driving thereof

ABSTRACT

Embodiments relate to a touch panel and a method of operating the touch panel. The touch panel includes first electrodes and second electrodes separated from and intersecting the first electrodes. The first electrodes are applied with a touch driving pulse during a first sensing mode and a second sensing mode. The second electrodes sense a first touch sense signal responsive to the touch driving pulse in the first sensing mode. A subset of the second electrodes senses a second touch sense signal responsive to the touch driving pulse in the second sensing mode.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the Korean Patent Application No.10-2014-0076794 filed on Jun. 23, 2014, which is hereby incorporated byreference as if fully set forth herein.

BACKGROUND

1. Field of the Disclosure

Embodiments of the present invention relate to a touch panel, and moreparticularly, to a touch panel enabling both touch force sensing andtouch point sensing, and an apparatus for driving thereof.

2. Discussion of the Related Art

A touch panel is a type of input device that is included in imagedisplaying devices such as Liquid Crystal Displays (LCDs), FieldEmission Displays (FEDs), Plasma Display Panel (PDPs),Electroluminescent Displays (ELDs), Electrophoretic Display (EPDs), andOrganic Light Emitting Devices (OLEDs), and allows a user to inputinformation by pressing or touching a touch sensor of a screen with afinger, a pen or the like while a user looks at the screen of the imagedisplaying device.

Recently, the touch panel is widely used for an input device of portableinformation devices such as smart phone and table PC, and also used foran input device of electronic equipment such as computer monitor,monitor and television.

According to a touch sensing method, the touch panel may be classifiedinto a resistive type, a capacitance type, and an infrared sensing type.The capacitance touch panel has attracted great attentions owing toadvantages of easy manufacturing method and sensitivity. The capacitancetouch panel may be classified into a mutual capacitance type and a selfcapacitance type. In comparison to the self capacitance type touchpanel, the mutual capacitance type touch panel is advantageous in thatit enables a multi-touch input.

In case of a general touch panel, a touch point may be sensed by the useof finger or pen. However, it is difficult to sense a touch force, thatis, touch pressure. Accordingly, U.S. Patent Application PublicationNumber 2014/0062933 published on Mar. 6, 2015 (hereinafter, referred toas “'933 Patent Document”) discloses a capacitance touch panel whichsenses both touch force and touch point.

As shown in FIG. 1, in case of the capacitance touch panel disclosed inthe '933 Patent Document, a touch force is sensed by a change ofcapacitance (Cm1) in accordance with the decrease of distance in betweena pair of force sensing electrodes 12 and 22 being overlapped with eachother and being parallel to each other, and a touch point is sensed by achange of capacitance (Cm2) in accordance with a fringe field in betweena pair of point sensing electrodes 14 and 24 being not overlapped witheach other and crossing each other.

However, the capacitance touch panel disclosed in the '933 PatentDocument has the following disadvantages.

The force sensing electrodes 12 and 22 for sensing the touch force areseparated from the point sensing electrodes 14 and 24 for sensing thetouch point so that it causes a complicated electrode structure. Inaddition, a touch resolution is lowered due to the point sensingelectrodes 14 and 24 crossing each other.

Also, efficiency of sensing the touch force is proportional to an areaof the force sensing electrodes 12 and 22 facing each other. Thus, ifthe force sensing electrodes 12 and 22 are decreased in size so as toimprove the touch resolution, the efficiency of sensing the touch forceis lowered.

In order to improve the touch resolution, if the point sensingelectrodes 14 and 24 are overlapped with each other, the capacitance(Cm2) formed between the point sensing electrodes 14 and 24 ismaintained at a constant value without regard to a touch of conductiveobject, whereby the efficiency of sensing the touch point is lowered.

SUMMARY

Accordingly, embodiments of the present invention are directed to atouch panel that substantially obviates one or more problems due tolimitations and disadvantages of the related art, and an apparatus fordriving thereof.

An aspect of embodiments of the present invention is directed to providea touch panel which facilitates to improve both efficiency of sensing atouch force and efficiency of sensing a touch point, and an apparatusfor driving thereof.

In one or more embodiments, a touch panel includes first electrodes andsecond electrodes separated from and intersecting the first electrodes.The first electrodes are applied with a touch driving pulse during afirst sensing mode and a second sensing mode. The second electrodessense a first touch sense signal responsive to the touch driving pulsein the first sensing mode. A subset of the second electrodes senses asecond touch sense signal responsive to the touch driving pulse in thesecond sensing mode.

In one or more embodiments, the touch panel further includes an elasticdielectric member disposed between the first electrodes and the secondelectrodes.

In the first sensing mode, the second electrodes may sense the firsttouch sense signal based at least in part on a first capacitance betweenthe first electrodes and the second electrodes responsive to the touchdriving pulse. In the second sensing mode, the subset of the secondelectrodes may sense the second touch sense signal based at least inpart on a second capacitance between the first electrodes and the subsetof the second electrodes responsive to the touch driving pulse, wherethe second capacitance is less than the first capacitance.

In one or more embodiments, the second electrodes include touch sensingelectrodes and adjacent electrodes adjacent to the touch sensingelectrodes. The subset of the second electrodes may include the touchsensing electrodes but may exclude the adjacent electrodes. The adjacentelectrodes may have an elongated rectangular shape in parallel with thetouch sensing electrodes.

In the first sensing mode, the first touch sense signal from at leastone of the touch sensing electrodes and one or more of the adjacentelectrodes adjacent to said one of the touch sensing electrodes may besensed to determine a force of the touch on the touch panel. In thesecond sensing mode, the second touch sense signal from said one of thetouch sensing electrodes but excluding the adjacent electrodes adjacentto said one of the touch sensing electrodes may be sensed to determine alocation of the touch on the touch panel.

In the first sensing mode, the one or more adjacent electrodes may beelectrically coupled to said one of the touch sensing electrodes. In thesecond sensing mode, the one or more adjacent electrodes may beelectrically decoupled from said one of the touch sensing electrodes. Inthe second sensing mode, the one or more adjacent electrodes may be inan electrically floating state.

In one or more embodiments, the adjacent electrodes include firstadjacent electrodes and second adjacent electrodes, where each of thetouch sensing electrodes is disposed between one of the first adjacentelectrodes and one of the second adjacent electrodes. Said one of thefirst adjacent electrodes and said one of the second adjacent electrodesmay be physically connected to each other. The touch panel may furtherinclude first routing lines and second routing lines. Each of the firstrouting lines may be connected to corresponding one of the touch sensingelectrodes and each of the second routing lines may be connected tocorresponding one of the first adjacent electrodes.

In one or more embodiments, responsive to determining the location ofthe touch in the second sensing mode, one or more selected electrodesfrom the first electrodes corresponding to the location of the touch areapplied with the touch driving pulse to determine the force of the touchindividually one at a time.

In one or more embodiments, responsive to failing to determine thelocation of the touch in the second sensing mode, a group of electrodesfrom the first electrodes are applied with the touch driving pulse todetermine the force of the touch simultaneously.

In one or more embodiments, responsive to determining the force of thetouch through the group of electrodes, one or more selected electrodesfrom the group of electrodes may be applied with the touch driving pulseto determine the location and the force of the touch individually one ata time. Responsive to failing to determine the force of the touchthrough the group of electrodes, the first electrodes may be appliedwith the touch driving pulse to determine the location of the touch inthe second sensing mode.

Additional advantages and features of embodiments of the invention willbe set forth in part in the description which follows and in part willbecome apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice ofembodiments of the invention. The objectives and other advantages ofembodiments of the invention may be realized and attained by thestructure particularly pointed out in the written description and claimshereof as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description of embodiments of the presentinvention are exemplary and explanatory and are intended to providefurther explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings:

FIG. 1 is a cross sectional view illustrating a simplified arrangementof electrodes in a touch panel disclosed in the '933 Patent Document;

FIG. 2 illustrates a simplified structure of a touch panel according tothe first embodiment of the present invention;

FIG. 3 is a cross sectional view of the touch panel along I-I′ shown inFIG. 2;

FIG. 4 is a graph for explaining a change of capacitance in accordancewith a distance of electrodes overlapping each other with an elasticdielectric member interposed therebetween, shown in FIG. 2;

FIGS. 5A and 5B are cross sectional views of the touch panel shown inFIG. 2 illustrating a change of capacitance among electrodes overlappingeach other with an elastic dielectric member interposed in-between in atouch force sensing mode and a touch point sensing mode, respectively;

FIG. 6 illustrates a modified example of the touch panel according tothe first embodiment of the present invention;

FIG. 7 illustrates a simplified structure of a touch panel according tothe second embodiment of the present invention;

FIG. 8 is a cross sectional view of the touch panel along II-II′ shownin FIG. 7;

FIG. 9 illustrates a driving apparatus of a touch panel according to oneembodiment of the present invention;

FIG. 10 is a block diagram for explaining a touch driving circuit ofFIG. 9;

FIG. 11 illustrates a modified example of the touch panel in the drivingapparatus according to one embodiment of the present invention; and

FIG. 12 is a flow chart for explaining a driving method of the touchpanel according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the exemplary embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

Advantages and features of the present invention, and implementationmethods thereof will be clarified through following embodimentsdescribed with reference to the accompanying drawings. The presentinvention may, however, be embodied in different forms and should not beconstrued as limited to the embodiments set forth herein. Rather, theseembodiments are provided so that this disclosure will be thorough andcomplete, and will fully convey the scope of the present invention tothose skilled in the art. Further, the present invention is only definedby scopes of claims.

A shape, a size, a ratio, an angle, and a number disclosed in thedrawings for describing embodiments of the present invention are merelyan example, and thus, the present invention is not limited to theillustrated details. Like reference numerals refer to like elementsthroughout. In the following description, when the detailed descriptionof the relevant known function or configuration is determined tounnecessarily obscure the important point of the present invention, thedetailed description will be omitted. In a case where ‘comprise’,‘have’, and ‘include’ described in the present specification are used,another part may be added unless ‘only˜’ is used. The terms of asingular form may include plural forms unless referred to the contrary.In construing an element, the element is construed as including an errorregion although there is no explicit description.

In description of embodiments of the present invention, when a structure(for example, an electrode, a line, a wiring, a layer, or a contact) isdescribed as being formed at an upper portion/lower portion of anotherstructure or on/under the other structure, this description should beconstrued as including a case where the structures contact each otherand moreover, a case where a third structure is disposed therebetween.

In describing a time relationship, for example, when the temporal orderis described as ‘after˜’, ‘subsequent˜’, ‘next˜’, and ‘before˜’ a casewhich is not continuous may be included unless ‘just’ or ‘direct’ isused.

It will be understood that, although the terms “first”, “second”, etc.may be used herein to describe various elements, these elements shouldnot be limited by these terms. These terms are only used to distinguishone element from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of the present invention.

Features of various embodiments of the present invention may bepartially or overall coupled to or combined with each other, and may bevariously inter-operated with each other and driven technically as thoseskilled in the art can sufficiently understand. The embodiments of thepresent invention may be carried out independently from each other, ormay be carried out together in co-dependent relationship.

Hereinafter, a touch panel according to the embodiment of the presentinvention and an apparatus for driving thereof will be described withreference to the accompanying drawings.

FIG. 2 illustrates a simplified structure of a touch panel according tothe first embodiment of the present invention. FIG. 3 is a crosssectional view of the touch panel along I-I′ shown in FIG. 2.

Referring to FIGS. 2 and 3, a touch panel 100 according to the firstembodiment of the present invention is disposed (or attached to) on adisplay panel of an image displaying device (not shown). The touch panel100 according to the first embodiment of the present invention generatestouch point sensing data and/or touch force sensing data in accordancewith a user's touch, and provides the generated data to an external hostsystem (not shown). For example, if a display panel is a liquid crystaldisplay panel (or organic light emitting display panel) including anupper polarizing film, the touch panel 100 may be disposed on the upperpolarizing film, or may be disposed between an upper substrate and theupper polarizing film. The touch panel 100 may include a first substrate110 with a touch driving electrode (Tx), a second substrate 120 with atouch sensing electrode (Rx) and first and second dummy electrodes (Dxa,Dxb), and an elastic dielectric member 130 disposed between the firstand second substrates 110 and 120.

The first substrate 110 may be formed of a transparent plastic material.The first substrate 110 may be attached to an upper surface of displaypanel by the use of transparent adhesive (not shown).

The touch driving electrode (Tx) is provided in a first direction (X) onthe first substrate 110, wherein the touch driving electrode (Tx) isformed in a bar shape with a predetermined area. The touch drivingelectrode (Tx) is connected with a touch driving circuit (not shown)through a driving routing line (RL1), and is supplied with a touchdriving pulse from the touch driving circuit.

In the same manner as the first substrate 110, the second substrate 120may be formed of the transparent plastic material. The second substrate120 and the first substrate 110 face each other, and the elasticdielectric member 130 is interposed between the first substrate 110 andthe second substrate 120. In addition, a cover window (not shown) may beattached to an upper surface of the second substrate 120 by the use oftransparent adhesive.

The touch sensing electrode (Rx) is provided in a second direction (Y)on the second substrate 120 being overlapped with the touch drivingelectrode (Tx), and the touch sensing electrode (Rx) is formed in a barshape with a predetermined area. In this case, with respect to alongitudinal direction, a width of the touch sensing electrode (Rx) issmaller than a width of the touch driving electrode (Tx). The touchsensing electrode (Rx) is connected with the touch driving circuitthrough a sensing routing line (RL2), whereby the touch sensingelectrode (Rx) is used as a touch point/force sensing electrode forsensing a touch point or touch force.

The first dummy electrode (Dxa) is formed in a bar shape with apredetermined area, and is provided in parallel to one side of the touchsensing electrode (Rx) along the second direction (Y) on the secondsubstrate 120 being overlapped with the touch driving electrode (Tx). Inthis case, with respect to the longitudinal direction, the first dummyelectrode (Dxa) may be provided at a predetermined interval from oneside of the touch sensing electrode (Rx), and a width of the first dummyelectrode (Dxa) may be smaller than a width of the touch drivingelectrode (Tx), or may be the same as a width of the touch sensingelectrode (Rx). As the first dummy electrode (Dxa) is connected with thetouch driving circuit through a first dummy routing line (RL3), thefirst dummy electrode (Dxa) may be floating by the touch driving circuitor may be electrically connected with the touch sensing electrode (Rx)or sensing routing line (RL2). In more detail, the first dummy electrode(Dxa) may be electrically floating in a touch point sensing mode, or thefirst dummy electrode (Dxa) may be electrically connected with the touchsensing electrode (Rx) in a touch force sensing mode. Accordingly, thefirst dummy electrode (Dxa) is used as a touch force sensing electrodefor sensing the touch force, and the first dummy electrode (Dxa) is alsoused as a floating electrode to enable sensing the touch point.

The second dummy electrode (Dxb) is formed in a bar shape with apredetermined area, and the second dummy electrode (Dxb) is provided inparallel to the other side of the touch sensing electrode (Rx) along thesecond direction (Y) on the second substrate 120 being overlapped withthe touch driving electrode (Tx). In this case, with respect to thelongitudinal direction, the second dummy electrode (Dxb) may be providedat a predetermined interval from the other side of the touch sensingelectrode (Rx), and a width of the second dummy electrode (Dxb) may besmaller than a width of the touch driving electrode (Tx), or may be thesame as a width of the touch sensing electrode (Rx) or first dummyelectrode (Dxa). As the second dummy electrode (Dxb) is connected withthe touch driving circuit through a second dummy routing line (RL4), thesecond dummy electrode (Dxb) may be maintained in the floating state bythe touch driving circuit, or may be electrically connected with thetouch sensing electrode (Rx). In more detail, the second dummy electrode(Dxb) may be electrically floating for the touch point sensing mode, ormay be electrically connected with the touch sensing electrode (Rx) orsensing routing line (RL2) for the touch force sensing mode.Accordingly, the second dummy electrode (Dxb) is used as a touch forcesensing electrode for sensing the touch force, and the second dummyelectrode (Dxb) is used as a floating electrode to enable sensing thetouch point.

In FIGS. 2 and 3, each of the first and second dummy electrodes (Dxa,Dxb) is formed in one bar shape, but is not limited to this shape. Inorder to improve a transmittance of light emitted from the displaypanel, each of the first and second dummy electrodes (Dxa, Dxb) may beformed in a line structure, a mesh structure or a ladder structureincluding a plurality of dummy electrodes electrically connected withone another, or may include a plurality of slits at fixed intervals or aplurality of openings arranged in a grid pattern.

The elastic dielectric member 130 is interposed between the firstsubstrate 110 and the second substrate 120. In this case, the elasticdielectric member 130 may be attached to an upper surface of the firstsubstrate 110 or a lower surface of the second substrate 120 by the useof transparent adhesive. The elastic dielectric member 130 may be formedof a material with elasticity and high dielectric constant. For example,the elastic dielectric member 130 may be formed of PDMS(polydimethylsiloxane), acrylic or poly-urethane material, but not belimited to these materials. The elastic dielectric member 130 may beformed of any material with elasticity and high dielectric constant.

The elastic dielectric member 130 forms a capacitance (Cm1, Cm2, Cm3)among the touch sensing electrode (Rx), each of the first and seconddummy electrodes (Dxa, Dxb), and the touch driving electrode (Tx).Specifically, the elastic dielectric member 130 is changed in itselasticity by a user's touch force, and thus changed in its thickness,to thereby change the capacitance (Cm1, Cm2, Cm3). In this case, thecapacitance (Cm1, Cm2, Cm3) may be changed in accordance with eachdistance among the touch sensing electrode (Rx), each of the first andsecond dummy electrodes (Dxa, Dxb), and the touch driving electrode(Tx), as shown in FIG. 4. In this case, as the capacitance (Cm1, Cm2,Cm3) is inversely proportional to each distance among the electrodes,the touch force may be sensed by a force level algorithm for modeling anincreased variation of the capacitance (Cm1, Cm2, Cm3) in accordancewith the touch force.

As the elastic dielectric member 130 with elasticity and high dielectricconstant is interposed between the first and second substrates 110 and120, a first touch sensor (Cm1) for sensing the touch point or touchforce is formed at an intersection of the touch driving electrode (Tx)and the touch sensing electrode (Rx). The first touch sensor (Cm1) isformed by a dielectric constant of the elastic dielectric member 130,and a capacitance based on an overlapping area between the touch drivingelectrode (Tx) and the touch sensing electrode (Rx) and a distancebetween the touch driving electrode (Tx) and the touch sensing electrode(Rx). In this case, an electric charge corresponding to a touch drivingpulse supplied to the touch driving electrode (Tx) is charged in thefirst touch sensor (Cm1), and the electric charge of the first touchsensor (Cm1) is discharged to the touch sensing electrode (Rx). Anamount of electric charge in the first touch sensor (Cm1) variesaccording to whether or not there is a user's touch.

As shown in FIG. 5A, when the first dummy electrode (Dxa) iselectrically connected with the touch sensing electrode (Rx) or sensingrouting line (RL2) in accordance with the touch force sensing mode, thefirst dummy electrode (Dxa) functions as the touch force sensingelectrode which is identical to the touch sensing electrode (Rx),whereby a second touch sensor (Cm2) for sensing the touch force isformed at an intersection between the touch driving electrode (Tx) andthe first dummy electrode (Dxa).

The second touch sensor (Cm2) is formed by a dielectric constant of theelastic dielectric member 130, and a capacitance based on an overlappingarea between the touch driving electrode (Tx) and the first dummyelectrode (Dxa) and a distance between the touch driving electrode (Tx)and the first dummy electrode (Dxa). As shown in FIG. 4, the capacitanceof the second touch sensor (Cm2) varies in accordance with the distancebetween the touch driving electrode (Tx) and the first dummy electrode(Dxa). In this case, an electric charge corresponding to a touch drivingpulse (Tx_PWM) supplied to the touch driving electrode (Tx) is chargedin the second touch sensor (Cm2), and the electric charge of the secondtouch sensor (Cm2) is discharged to the first dummy electrode (Dxa). Anamount of electric charge in the second touch sensor (Cm2) varies inaccordance with the distance between the touch driving electrode (Tx)and the first dummy electrode (Dxa) by a user's touch force.

Meanwhile, as shown in FIG. 5B, when the first dummy electrode (Dxa) iselectrically floating without being connected with the touch sensingelectrode (Rx) in accordance with the touch point sensing mode, thecapacitance (Cm2) is not formed between the touch driving electrode (Tx)and the first dummy electrode (Dxa). Accordingly, the capacitance of thefirst touch sensor (Cm1) formed between the touch driving electrode (Tx)and the touch sensing electrode (Rx) is changed in accordance with thetouch by the use of conductive object, whereby it is possible to sensethe touch point, and furthermore to improve sensing efficiency of thetouch point.

As shown in FIG. 5A, when the second dummy electrode (Dxb) iselectrically connected with the touch sensing electrode (Rx) or sensingrouting line (RL2) in accordance with the touch force sensing mode, thesecond dummy electrode (Dxb) functions as the touch force sensingelectrode which is identical to the touch sensing electrode (Rx),whereby a third touch sensor (Cm3) for sensing the touch force is formedat an intersection between the touch driving electrode (Tx) and thesecond dummy electrode (Dxb). The third touch sensor (Cm3) is formed bya dielectric constant of the elastic dielectric member 130, and acapacitance based on an overlapping area between the touch drivingelectrode (Tx) and the second dummy electrode (Dxb) and a distancebetween the touch driving electrode (Tx) and the second dummy electrode(Dxb). As shown in FIG. 4, the capacitance of the third touch sensor(Cm3) varies in accordance with the distance between the touch drivingelectrode (Tx) and the second dummy electrode (Dxb). In this case, anelectric charge corresponding to a touch driving pulse (Tx_PWM) suppliedto the touch driving electrode (Tx) is charged in the third touch sensor(Cm3), and the electric charge of the third touch sensor (Cm3) isdischarged to the second dummy electrode (Dxb). An amount of electriccharge in the third touch sensor (Cm3) varies in accordance with thedistance between the touch driving electrode (Tx) and the second dummyelectrode (Dxb) by a user's touch force.

Meanwhile, as shown in FIG. 5B, when the second dummy electrode (Dxb) iselectrically floating without being connected with the touch sensingelectrode (Rx) in accordance with the touch point sensing mode, thecapacitance (Cm3) is not formed between the touch driving electrode (Tx)and the second dummy electrode (Dxb). Accordingly, the capacitance ofthe first touch sensor (Cm1) formed between the touch driving electrode(Tx) and the touch sensing electrode (Rx) is changed in accordance withthe touch by the use of conductive object, whereby it is possible tosense the touch point, and furthermore to improve sensing efficiency ofthe touch point.

Additionally, each of the touch driving electrode (Tx) and the touchsensing electrode (Rx) may be formed in a circular or diamond shape, andeach of the first and second dummy electrodes (Dxa, Dxb) may be formedto surround the touch sensing electrode (Rx) on halves. Preferably, eachof the electrodes (Tx, Rx, Dxa, Dxb) is formed in the bar shape in orderto sufficiently secure the capacitance for sensing the touch point andthe capacitance for sensing the touch force, as mentioned above.

The touch panel 100 according to the first embodiment of the presentinvention facilitates to improve the sensing efficiency of the touchpoint by electrically floating the first and second dummy electrodes(Dxa, Dxb) in accordance with the touch point sensing mode, and also toimprove the sensing efficiency of the touch force by increasing the areaof the force sensing electrode for sensing the touch force through theelectrical connection between the touch sensing electrode (Rx) and thefirst and second dummy electrodes (Dxa, Dxb). Hence, a largercapacitance is charged between the touch driving electrode (Tx) and acombination of the touch sensing electrode (Rx) and the first dummyelectrode (Dxa) and/or the second dummy electrode (Dxb) in the touchforce sensing mode, compared to a capacitance charged between the touchdriving electrode (Tx) and the touch sensing electrode (Rx) in the touchpoint sensing mode. Large capacitance charged between the touch drivingelectrode (Tx) and the combination of the touch sensing electrode (Rx)and the first dummy electrode (Dxa) and/or the second dummy electrode(Dxb) in the touch force sensing mode enables accurate sensing of touchforce. In addition, less capacitance charged between the touch drivingelectrode (Tx) and the touch sensing electrode (Rx) in the touch pointsensing mode enables enough fringe field to be formed between the touchdriving electrode (Tx) and the touch sensing electrode (Rx) to allowaccurate sensing of touch point (or whether a specific electrode istouched or not). Eventually, the touch panel 100 according to the firstembodiment of the present invention enables to improve both the touchforce sensing efficiency and the touch point sensing efficiency.

FIG. 6 illustrates a modified example of the touch panel according tothe first embodiment of the present invention, wherein one side of thefirst dummy electrode is electrically connected with one side of thesecond dummy electrode. Hereinafter, only the first and second dummyelectrodes will be described in detail as follows.

One side of the first dummy electrode (Dxa) is electrically connectedwith one side of the second dummy electrode (Dxb) through a dummy bridgeelectrode (Dxc).

The dummy bridge electrode (Dxc) is provided at a predetermined intervalfrom one side of the touch sensing electrode (Rx) while being inparallel to one side of the touch sensing electrode (Rx), whereby thedummy bridge electrode (Dxc) is electrically connected with both oneside of the first dummy electrode (Dxa) and one side of the second dummyelectrode (Dxb). Accordingly, the dummy bridge electrode (Dxc) and thefirst and second dummy electrodes (Dxa, Dxb) are provided in shape of“⊂” or “⊃”.

Additionally, one side of the first dummy electrode (Dxa) iselectrically connected with one side of the second dummy electrode (Dxb)through the dummy bridge electrode (Dxc), whereby it is possible to omitany one of the first and second dummy routing lines (RL3, RL4).Accordingly, a width of edge in the touch panel 100 provided with therouting line is reduced so that a bezel width of the touch panel 100 isreduced.

FIG. 7 illustrates a simplified structure of a touch panel 200 accordingto the second embodiment of the present invention. FIG. 8 is a crosssectional view of the touch panel 200 along II-II′ shown in FIG. 7.

As shown in FIG. 7, a touch panel 200 according to the second embodimentof the present invention is obtained by providing the touch drivingelectrode (Tx) on a lower surface of the elastic dielectric member 130,and providing the touch sensing electrode (Rx) and the first and seconddummy electrodes (Dxa, Dxb) on an upper surface of the elasticdielectric member 130 in the aforementioned touch panel 100 according tothe first embodiment of the present invention. That is, in case of thetouch panel 200 according to the second embodiment of the presentinvention, the aforementioned first and second substrates 110 and 120are removed from the touch panel 200. Except that the first and secondsubstrates 110 and 120 are removed from the touch panel 200, the touchpanel 200 according to the second embodiment of the present invention isidentical in electrode structure to the touch panel 100 of FIG. 6,whereby it is possible to sense both the touch point and the touchforce, and to realize a thin profile of the touch panel by thesimplified structure.

In FIGS. 7 and 8, one side of the first dummy electrode (Dxa) iselectrically connected with one side of the second dummy electrode (Dxb)through the dummy bridge electrode (Dxc), but is not limited to thisstructure. That is, it is possible to omit the dummy bridge electrode(Dxc). In this case, the electrode structure of the touch panel 200according to the second embodiment of the present invention may beidentical to the electrode structure of the touch panel 100 shown inFIG. 2, whereby the touch driving electrode (Tx) may be formed on thelower surface of the elastic dielectric member 130, and the touchsensing electrode (Rx) and the first and second dummy electrodes (Dxa,Dxb) may be formed on the upper surface of the elastic dielectric member130.

The lower surface of the touch panel 200 according to the secondembodiment of the present invention, that is, the touch drivingelectrode (Tx) may be attached to the upper surface of the display panelby the use of transparent adhesive. The upper surface of the touch panel200 according to the second embodiment of the present invention, thatis, the touch sensing electrode (Rx) and the first and second dummyelectrodes (Dxa, Dxb) may be covered with the cover window by the use oftransparent adhesive.

In the aforementioned first and second embodiments of the presentinvention, each of the touch panels 100 and 200 includes the first andsecond dummy electrodes (Dxa, Dxb), but is not limited to thisstructure. According to a modified example of the present invention,each of the touch panels 100 and 200 may include the first and seconddummy electrodes (Dxa, Dxb), wherein any one of the first and seconddummy electrodes (Dxa, Dxb) may be electrically floating without regardto the sensing mode, and another thereof may be electrically floating orconnected with the touch sensing electrode in accordance with thesensing mode. According to another modified example of the presentinvention, each of the touch panels 100 and 200 may include any one ofthe first and second dummy electrodes (Dxa, Dxb). In this case, it maycause the decrease in the area of electrode used as the touch sensingelectrode for sensing the touch force in accordance with the touch forcesensing mode, however, it also may cause the increase in the area ofelectrode used as the touch sensing electrode for sensing the touchpoint in accordance with the touch point sensing mode, to therebyimprove the efficiency for sensing the touch point.

FIG. 9 illustrates a driving apparatus of touch panel according to oneembodiment of the present invention. FIG. 10 is a block diagram forexplaining a touch driving circuit of FIG. 9.

Referring to FIGS. 9 and 10, the driving apparatus of touch panelaccording to one embodiment of the present invention may include a touchpanel 300 and a touch driving circuit 400.

The touch panel 300 may include first to n-th touch driving electrodes(Tx1˜Txn), an elastic dielectric member (See FIG. 2) disposed on thefirst to n-th touch driving electrodes (Tx1˜Txn), and first to m-thtouch sensing electrode groups (Rx_G1˜Rx_Gm) disposed on the elasticdielectric member, and respectively overlapped and intersected with therespective first to n-th touch driving electrodes (Tx1˜Txn).

The first to n-th touch driving electrodes (Tx1˜Txn) are provided atfixed intervals in a first direction (X) on a touch sensing area 300 aof the touch panel 300. The first to n-th touch driving electrodes(Tx1˜Txn) are connected with a touch driving circuit 400 through a padportion (PP) and corresponding driving routing line (RL1) formed in afirst edge of the touch panel 300. The first to n-th touch drivingelectrode (Tx1˜Txn) may be formed on the first substrate (See FIG. 2),or may be formed on the lower surface of the elastic dielectric member(See FIG. 7).

The elastic dielectric member may be formed of a material withelasticity and dielectric constant, and may be disposed on the first ton-th touch driving electrodes (Tx1 Txn). This elastic dielectric memberis the same as the elastic dielectric member 130 shown in FIGS. 2 and 3,whereby a detailed description for the elastic dielectric member will beomitted.

The first to m-th touch sensing electrode groups (Rx_G1˜Rx_Gm) areformed at fixed intervals in a second direction (Y) on the touch sensingarea 300 a of the touch panel 300, wherein the first to m-th touchsensing electrode groups (Rx_G1˜Rx_Gm) respectively intersect with thefirst to n-th touch driving electrodes (Tx1˜Txn). The first to m-thtouch sensing electrode groups (Rx_G1˜Rx_Gm) may be formed on the secondsubstrate (See FIG. 2), or may be formed on the upper surface of theelastic dielectric member (See FIG. 7).

Each of the first to m-th touch sensing electrode groups (Rx_G1˜Rx_Gm)may include the touch sensing electrode (Rx), first dummy electrode(Dxa) and second dummy electrode (Dxb).

The touch sensing electrode (Rx) is used as a touch point/force sensingelectrode for sensing a touch point or touch force. The touch sensingelectrode (Rx) is connected with the touch driving circuit 400 throughthe pad portion (PP) and sensing routing line (RL2) formed in a secondedge of the touch panel 300. The touch sensing electrode (Rx) isidentical to the touch sensing electrode (Rx) shown in FIGS. 2 and 3,wherein a detailed description for the touch sensing electrode (Rx) willbe omitted.

The first dummy electrode (Dxa) may be used only as the touch forcesensing electrode for sensing the touch force. The first dummy electrode(Dxa) is connected with the touch driving circuit 400 through the padportion (PP) and first dummy routing line (RL3) formed in the secondedge of the touch panel 300. That is, the first dummy electrode (Dxa)for each of the first to m-th touch sensing electrode groups(Rx_G1˜Rx_Gm) may be electrically floating by the touch driving circuit400, or may be electrically connected with the touch sensing electrode(Rx) or sensing routing line (RL2). The first dummy electrode (Dxa) isidentical to the first dummy electrode (Dxa) shown in FIGS. 2 and 3,whereby a detailed description for the first dummy electrode (Dxa) willbe omitted.

The second dummy electrode (Dxb) may be used only as the touch forcesensing electrode for sensing the touch force. The second dummyelectrode (Dxb) is connected with the touch driving circuit 400 throughthe pad portion (PP) and second dummy routing line (RL4) formed in thesecond edge of the touch panel 300. That is, the second dummy electrode(Dxb) for each of the first to m-th touch sensing electrode groups(Rx_G1˜Rx_Gm) may be electrically floating by the touch driving circuit400, or may be electrically connected with the touch sensing electrode(Rx) or sensing routing line (RL2). The second dummy electrode (Dxb) isidentical to the second dummy electrode (Dxb) shown in FIGS. 2 and 3,whereby a detailed description for the second dummy electrode (Dxb) willbe omitted.

The touch driving circuit 400 is provided on a flexible circuit film 500attached to the pad portion (PP) of the touch panel 300, and isconnected with each of the routing lines (RL1, RL2, RL3, RL4) throughthe pad portion (PP). Alternatively, the touch driving circuit 400 maybe provided on a printed circuit board (not shown). In this case, thetouch driving circuit 400 may be connected with each of the routinglines (RL1, RL2, RL3, RL4) through a flexible circuit film (not shown)connected between the printed circuit board and the pad portion (PP) ofthe touch panel 300.

The touch driving circuit 400 supplies a touch driving pulse (Tx_PWM) toeach of the first to n-th touch driving electrodes (Tx1˜Txn), and alsosenses a touch sense signal indicating a change of capacitance througheach of the first to m-th touch sensing electrode groups (Rx_G1˜Rx_Gm).For example, the touch driving circuit 400 drives the touch panel 300 bya time division method in accordance with the touch point sensing modeor touch force sensing mode, to thereby generate touch point sensingdata (Pdata) or touch force sensing data (Fdata).

For the touch point sensing mode, after the touch driving circuit 400electrically floats the first and second dummy electrodes (Dxa, Dxb) foreach of the plurality of touch sensing electrode groups (Rx_G1˜Rx_Gm),the touch driving circuit 400 sequentially supplies the touch drivingpulse (Tx_PWM) to each of the first to n-th touch driving electrodes(Tx1˜Txn), and simultaneously senses the touch sense signal indicatingthe change of charge amount in the first touch sensor (Cm1, See FIG. 5B)through the touch sensing electrode (Rx) for each of the first to m-thtouch sensing electrode groups (Rx_G1˜Rx_Gm), to thereby generate touchpoint sensing data (Pdata).

For the touch force sensing mode, after the touch driving circuit 400electrically connects the first and second dummy electrodes (Dxa, Dxb)to the touch sensing electrode (Rx) in a unit of the first to m-th touchsensing electrode groups (Rx_G1˜Rx_Gm), the touch driving circuit 400sequentially supplies the touch driving pulse (Tx_PWM) to each of thefirst to n-th touch driving electrodes (Tx1˜Txn), and simultaneouslysenses the touch sense signal indicating the change of charge amount inthe first to third touch sensors (Cm1, Cm2, Cm3) through the touchsensing electrode (Rx) for each of the first to m-th touch sensingelectrode groups (Rx_G1˜Rx_Gm), to thereby generate touch force sensingdata (F data).

The touch driving circuit 400 according to one embodiment of the presentinvention may include a timing generating part 410, a driving pulsesupplying part 420, an electrode connecting part 430, a sensing part 440and a sensing data processing part 450. The touch driving circuit 400 ofthe above structure may be integrated as one ROIC (Readout IntegratedCircuit) chip. However, the sensing data processing part 450 may beimplemented as MCU (Micro Controller Unit) of host system without beingintegrated with the ROIC chip.

The timing generating part 410 generates a sensing start signal (PHT) inresponse to a touch mode signal (TMS) supplied from the MCU of hostsystem, and controls a driving timing for each of the driving pulsesupplying part 420 and the sensing part 440. In this case, the touchmode signal (TMS) may be any one selected among a touch point sensingmode signal, a touch force sequential sensing mode signal, a touch forcepartial sensing mode signal and a touch force group sensing mode signal.Accordingly, the timing generating part 410 may generate touch controlsignals including sensing start signal (PHT), Tx channel setup signal,electrode connection signal (ECS), Rx channel setup signal and touchreport synchronization signal (TRSS) on the basis of touch mode signal(TMS).

The driving pulse supplying part 420 supplies the touch driving pulse(Tx_PWM) to the touch driving electrode (Tx1˜Txn) on the basis ofsensing start signal (PHT) and Tx channel setup signal supplied from thetiming generating part 410. That is, the driving pulse supplying part420 selects a TX channel, to which the touch driving pulse (Tx_PWM) isto be output, in response to the TX channel setup signal of the timinggenerating part 410, generates the touch driving pulse (Tx_PWM)synchronized with the sensing start signal (PHT), and supplies the touchdriving pulse (Tx_PWM) to the corresponding touch driving electrode(Tx1˜Txn) through the driving routing line (Tx1˜Txn) connected with theselected Tx channel. For example, in case of the touch point sensingmode or touch force sequential sensing mode, the driving pulse supplyingpart 420 may sequentially supply the touch driving pulse (Tx_PWM) to thefirst to n-th touch driving electrodes (Tx1˜Txn). In case of the touchforce partial sensing mode, the driving pulse supplying part 420 maysequentially supply the touch driving pulse (Tx_PWM) to the plurality oftouch driving electrodes partially selected among the first to n-thtouch driving electrodes (Tx1˜Txn). The touch force partial sensing modeherein refers to a mode in which one or more touch driving electrodes(TX) are driven individually one at a time. In case of the touch forcegroup sensing mode, the driving pulse supplying part 420 maysequentially supply the touch driving pulse (Tx_PWM) to a plurality ofgroups, wherein each group may include the two or more touch drivingelectrodes among the first to n-th touch driving electrodes (Tx1˜Txn).The touch force group sensing mode herein refers to a mode in whichtouch driving electrodes (TX) in a group are driven simultaneously.

In response to the electrode connection signal (ECS) supplied from thetiming generating part 410, the electrode connecting part 430electrically floats the first and second dummy electrodes (Dxa, Dxb) ina unit of the first to m-th touch sensing electrode groups (Rx_G1˜Rx_Gm)or electrically connects the first and second dummy electrodes (Dxa,Dxb) to the touch sensing electrode (Rx). For example, the electrodeconnecting part 430 electrically floats the first and second dummyrouting lines (RL3, RL4) for each of the first to m-th touch sensingelectrodes groups (Rx_G1˜Rx_Gm) in response to the electrode connectionsignal (ECS) in accordance with the touch point sensing mode, wherebythe first and second dummy electrodes (Dxa, Dxb) are electricallyfloating in a unit of the first to m-th touch sensing electrode groups(Rx_G1˜Rx_Gm). Also, the electrode connecting part 430 electricallyconnects the first and second dummy routing lines (RL3, RL4) to thesensing routing line (RL2) in a unit of the first to m-th touch sensingelectrode groups (Rx_G1˜Rx_Gm) in response to the electrode connectionsignal (ECS) in accordance with the touch force sequential sensing mode,the touch force partial sensing mode and the touch force group sensingmode.

The sensing part 440 generates a sensing signal obtained by sensing thechange of charge amount in the touch sensor through the touch sensingelectrode (Rx) for each of the first to m-th touch sensing electrodegroups (Rx_G1˜Rx_Gm) connected with the electrode connecting part 430 onthe basis of sensing start signal (PHT) and Rx channel setup signal, andgenerates touch point sensing data (Pdata) or touch force sensing data(Fdata) by an analog-to-digital conversion of the sensing signal. Forexample, in case of the touch point sensing mode, the sensing part 440senses the change of charge amount in the touch sensor (Cm1, See FIG.5B) through the touch sensing electrode (Rx) for each of the first tom-th touch sensing electrode groups (Rx_G1˜Rx_Gm), and generates thetouch point sensing data (Pdata) based on the change of charge amount.Also, in case of the touch force sequential sensing mode, touch forcepartial sensing mode and touch force group sensing mode, the sensingpart 440 senses the change of charge amount in the touch sensor (Cm1,Cm2 and Cm3, See FIG. 5A) through the first and second dummy electrodes(Dxa, Dxb) and touch sensing electrode (Rx) for each of the first tom-th touch sensing electrode groups (Rx_G1˜Rx_Gm), and generates thetouch force sensing data (Fdata) based on the change of charge amount.

The sensing part 440 according to one embodiment of the presentinvention may generate the sensing signal by amplifying a difference ofthe signals from the adjacent two Rx channels, and sampling theamplified signal. The sensing part 440 according to one embodiment ofthe present invention amplifies the difference between the signals ofthe adjacent two touch sensing electrodes and reduces noise ingredientinput due to a parasitic capacitance of the touch panel 300, to therebyimprove a signal-to-noise ratio. To this end, the sensing part 440according to one embodiment of the present invention may include anintegrator comprising a differential amplifier.

The sensing part 440 according to another embodiment of the presentinvention may compare a signal received from one Rx channel with areference voltage, and may generate the sensing signal based on thecomparison result. In this case, the sensing part 440 according toanother embodiment of the present invention may include a comparator.

The sensing data processing part 450 receives the touch point sensingdata (Pdada) or touch force sensing data (Fdata) from the sensing part440, sequentially stores the received data in an internal memory, andtransmits the touch point sensing data (Pdata) or touch force sensingdata (Fdata) stored in the internal memory to the MCU of host system inresponse to the touch report synchronization signal (TRSS) in accordancewith a preset interface method.

The MCU of host system receives the touch point sensing data (Pdata)from the sensing data processing part 450, compares the received touchpoint sensing data (Pdata) with a preset point sensing threshold valueto determine whether or not there is a user's touch and the touch pointcoordinates. In one aspect, the MCU determines that a coordinate of thetouch panel is touched, if the touch point sensing data corresponding tothe coordinate is larger than the point sensing threshold value. Thatis, the MCU calculates the touch point coordinates value (XYcoordinates) based on point information (X-coordinate) of the touchsensing electrode (Rx) with the touch point sensing data (Pdata) andpoint information (Y-coordinate) of the touch driving electrode (Tx)being driven. In addition, the MCU may calculate the number of touchpoints from the calculated touch point coordinates, calculate the numberof times being touched by counting the calculated number of touch pointsin a unit time period, or calculate a touch continuance time in a unittime period.

Also, the MCU of host system receives the touch force sensing data(Fdata) from the sensing data processing part 450, compares the receivedtouch force sensing data (Fdata) with a preset force sensing thresholdvalue, and calculates the touch point coordinates and a size of touchforce by the use of touch force sensing data, if the touch force sensingdata is larger than the force sensing threshold value. That is, the MCUcalculates the touch force coordinates value (XY coordinates) based onpoint information (X-coordinate) of the touch sensing electrode (Rx)with the touch force sensing data (Fdata) and point information(Y-coordinate) of the touch driving electrode (Tx) being driven, andalso calculates the size of touch force based on a size of the touchforce sensing data (Fdata).

Additionally, the touch driving circuit 400 may comprise a touch MCUwhich calculates whether or not there is a user's touch, the touch pointcoordinates and the size of touch force by the use of touch pointsensing data (Pdata) and/or touch force sensing data (Fdata), andtransmits the calculated results to the MCU. In this case, the MCU ofthe host system may only execute an application program linked to thetouch point coordinates and the size of touch force provided from thetouch MCU of host system.

Meanwhile, as shown in FIGS. 6 and 11, each of the first to m-th touchsensing electrode groups (Rx_G1˜Rx_Gm) may further include the dummybridge electrode (Dxc) for electrically connecting one side of the firstdummy electrode (Dxa) with one side of the second dummy electrode (Dxb).In this case, one side of the first dummy electrode (Dxa) iselectrically connected with one side of the second dummy electrode (Dxb)through the dummy bridge electrode (Dxc) in a unit of the first to m-thtouch sensing electrode groups (Rx_G1˜Rx_Gm), whereby any one of thefirst and second dummy routing lines (RL3, RL4), for example, the seconddummy routing line (RL4) may be omitted. Accordingly, the electrodeconnecting part 430 of the touch driving circuit 400 electrically floatsthe first dummy routing line (RL3) in response to the electrodeconnection signal (ECS) in accordance with the touch point sensing mode,whereby the electrode connecting part 430 electrically floats the firstand second dummy electrodes (Dxa, Dxb) for each of the first to m-thtouch sensing electrode groups (Rx_G1˜Rx_Gm). The electrode connectingpart 430 electrically connects the first dummy routing line (RL3) withthe sensing routing line (RL2) in response to the electrode connectionsignal (ECS) in accordance with the touch force sequential sensing mode,the touch force partial sensing mode and the touch force group sensingmode, whereby the first and second dummy electrodes (Dxa, Dxb) areelectrically connected with the corresponding touch sensing electrode(Rx) in a unit of the first to m-th touch sensing electrode groups(Rx_G1˜Rx_Gm).

FIG. 12 is a flow chart for explaining a driving method of the touchpanel according to one embodiment of the present invention.

In connection with FIGS. 9 and 10, FIG. 12 is a flow chart forexplaining the driving method of the touch panel according to oneembodiment of the present invention.

First, after the touch driving circuit 400 electrically floats the firstand second dummy electrodes (Dxa, Dxb) for each of the first to m-thtouch sensing electrode groups (Rx_G1˜Rx_Gm) in accordance with thetouch point sensing mode, the touch driving circuit 400 sequentiallysupplies the touch driving pulse (Tx_PWM) to each of the first to n-thtouch driving electrodes (Tx1˜Txn), and simultaneously senses the changeof charge amount in the first touch sensor (Cm1, See FIG. 5B) throughthe touch sensing electrode (Rx) for each of the first to m-th touchsensing electrode groups (Rx_G1˜Rx_Gm), to thereby generate the touchpoint sensing data (Pdata) (S100).

For the touch point sensing mode, the MCU determines whether or notthere is the touch point sensing on the basis of preset point sensingthreshold value and touch point sensing data (Pdata) supplied from thetouch driving circuit 400 (S200). Based on the determination result, ifthere is the touch point sensing (′Yes' of S200), touch point areainformation is generated, and the touch force partial sensing modesignal is generated and is supplied to the touch driving circuit 400.

Thereafter, after the touch driving circuit 400 electrically connectsthe first and second dummy electrodes (Dxa, Dxb) to the touch sensingelectrode (Rx) in a unit of the touch sensing electrode group(Rx_G1˜Rx_Gm) corresponding to the touch point area information inresponse to the touch force partial sensing mode signal and the touchpoint area information supplied from the MCU, the touch driving circuit400 sequentially supplies the touch driving pulse (Tx_PWM) to one ormore of the touch driving electrode (Tx1˜Txn) corresponding to the touchpoint area information individually one at a time, and simultaneouslysenses the change of charge amount in the first to third touch sensors(Cm1, Cm2 and Cm3, See FIG. 5A) through the touch sensing electrode (Rx)of the corresponding touch sensing electrode group (Rx_G1˜Rx_Gm), tothereby generate the touch force sensing data (Fdata) (S110).

For the touch force partial sensing mode, the MCU determines whether ornot there is the touch force sensing on the basis of touch force sensingdata (Fdata) and preset force sensing threshold value (S210). Based onthe determination result, if there is the touch force sensing (‘Yes’ ofS210) by the touch force sensing data (Fdata), the touch pointcoordinates based on the touch point sensing data (Pdata) and the sizeof touch force are calculated and are supplied to the host system(S220). Meanwhile, if there is no touch force sensing (‘No’ of S210) bythe touch force sensing data (Fdata), the touch point coordinates basedon the touch point sensing data (Pdata) generated by the prior touchpoint sensing mode is calculated and is provided to the host system(S230).

In the step S200 of the touch point sensing mode, if the MCU determinesthat there is no touch point sensing (‘No’ of S200), the touch forcegroup sensing mode signal is generated and is provided to the touchdriving circuit 400.

After the touch driving circuit 400 electrically connects the first andsecond dummy electrodes (Dxa, Dxb) to the touch sensing electrode (Rx)in a unit of the first to m-th touch sensing electrode groups(Rx_G1˜Rx_Gm) in response to the touch force group sensing mode signalsupplied from the MCU, the touch driving circuit 400 sequentiallysupplies the touch driving pulse (Tx_PWM) to the plurality of touchdriving electrode groups, wherein each touch driving electrode groupcomprises the two or more touch driving electrodes that are suppliedwith the touch driving pulse simultaneously, and senses the change ofcharge amount in the first to third touch sensors (Cm1, Cm2 and Cm3, SeeFIG. 5A) through the touch sensing electrode (Rx) of the correspondingtouch sensing electrode group (Rx_G1˜Rx_Gm), to thereby generate thetouch force sensing data (Fdata) (S120).

For the touch force group sensing mode, the MCU determines whether ornot there is the touch force sensing on the basis of touch force data(Fdata) and force sensing threshold value (S240). Based on thedetermination result, if there is the touch force sensing (‘Yes’ ofS240) by the touch force sensing data (Fdata), touch force areainformation based on the touch force sensing data (Fdata) is generated,and the touch force partial sensing mode signal is generated andsupplied to the touch driving circuit 400.

After the touch driving circuit 400 electrically connects the first andsecond dummy electrodes (Dxa, Dxb) to the touch sensing electrode (Rx)in a unit of the touch sensing electrode group (Rx_G1˜Rx_Gm)corresponding to the touch force area information in response to thetouch force partial sensing mode signal and the touch force areainformation supplied from the MCU, the touch driving circuit 400sequentially supplies the touch driving pulse (Tx_PWM) to the touchdriving electrode (Tx1˜Txn) corresponding to the touch force areainformation individually one at a time, and senses the change of chargeamount in the first to third touch sensors (Cm1, Cm2 and Cm3, See FIG.5A) through the touch sensing electrode (Rx) of the corresponding touchsensing electrode group (Rx_G1˜Rx_Gm), to thereby generate the touchforce sensing data (Fdata) (S130).

For the touch force partial sensing mode, the MCU calculates the touchpoint coordinates and the size of touch force, if touch force sensingdata (Fdata) supplied from the touch driving circuit 400 is larger thanthe preset force sensing threshold value, and provides the calculatedtouch point coordinates and the size of touch force to the host system(S250).

In the step S240 of the touch force group sensing mode, if the MCUdetermines that there is no touch force sensing (′No′ of S240), the MCUgenerates the touch point sensing mode signal for the touch pointsensing mode of the step S100, and supplies the generated signal to thetouch driving circuit 400.

In the aforementioned apparatus and method for driving the touch panelaccording to one embodiment of the present invention, each of the touchsensing electrode groups (Rx_G1˜Rx_Gm) of the touch panel 300 includesthe first and second dummy electrodes (Dxa, Dxb), but is not limited tothis structure. According to a modified example, each of the touchsensing electrode groups (Rx_G1˜Rx_Gm) may include the first and seconddummy electrodes (Dxa, Dxb), wherein any one of the first and seconddummy electrodes (Dxa, Dxb) may be electrically floating without regardto the sensing mode, and another thereof may be electrically floating orconnected with the touch sensing electrode in accordance with thesensing mode. According to another modified example, each of the touchsensing electrode groups (Rx_G1˜Rx_Gm) may include any one of the firstand second dummy electrodes (Dxa, Dxb). In this case, it may cause thedecrease in the area of electrode used as the touch sensing electrodefor sensing the touch force in accordance with the touch force sensingmode, however, it also may cause the increase in the area of electrodeused as the touch sensing electrode for sensing the touch point inaccordance with the touch point sensing mode, to thereby improve theefficiency for sensing the touch point.

For the touch point sensing, the first and second dummy electrodes (Dxa,Dxb) are electrically floating, and then the touch point sensing mode iscarried out so that it is possible to improve the efficiency for thetouch point sensing. For the touch force sensing, the area of thesensing electrode is increased by electrically connecting the first andsecond dummy electrodes (Dxa, Dxb) with the touch sensing electrode(Rx), and then the touch force sensing mode is carried out so that it ispossible to improve the efficiency for the touch force sensing.Specifically, the touch point sensing and the touch force sensing arecarried out in the time division driving method, wherein the touch forcesensing is carried out dividedly by the touch force group sensing andthe touch force partial sensing, whereby it is possible to overcome aproblem of the increase in touch driving time caused by the timedivision driving method.

According to the embodiments of the present invention, the area of thetouch sensing electrode overlapped with the touch driving electrode isadjusted in accordance with the touch point sensing and the touch forcesensing so that it is possible to improve both touch point sensingefficiency and touch force sensing efficiency.

Also, even though the time division driving method is used for the touchpoint sensing and the touch force sensing, the partial sensing or groupsensing is selectively carried out so that it is possible to overcomethe problem of the increase in touch driving time caused by the timedivision driving method.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to embodiments of the presentinvention without departing from the spirit or scope of the invention.Thus, it is intended that the present invention covers the modificationsand variations of this invention provided they come within the scope ofthe appended claims and their equivalents.

What is claimed is:
 1. A touch panel comprising: first electrodes applied with a touch driving pulse during a first sensing mode and a second sensing mode; and second electrodes separated from and intersecting the first electrodes, the second electrodes to sense a first touch sense signal responsive to the touch driving pulse in the first sensing mode, and a subset of the second electrodes to sense a second touch sense signal responsive to the touch driving pulse in the second sensing mode.
 2. The touch panel of claim 1, further comprising: an elastic dielectric member disposed between the first electrodes and the second electrodes.
 3. The touch panel of claim 1, wherein: in the first sensing mode, the second electrodes are configured to sense the first touch sense signal based at least in part on a first capacitance between the first electrodes and the second electrodes responsive to the touch driving pulse, and in the second sensing mode, the subset of the second electrodes is configured to sense the second touch sense signal based at least in part on a second capacitance between the first electrodes and the subset of the second electrodes responsive to the touch driving pulse, the second capacitance less than the first capacitance.
 4. The touch panel of claim 1, wherein the second electrodes include touch sensing electrodes and adjacent electrodes adjacent to the touch sensing electrodes, and wherein the subset of the second electrodes includes the touch sensing electrodes but excludes the adjacent electrodes.
 5. The touch panel of claim 4, wherein the adjacent electrodes have an elongated rectangular shape in parallel with the touch sensing electrodes.
 6. The touch panel of claim 4, wherein: in the first sensing mode, the first touch sense signal from at least one of the touch sensing electrodes and one or more of the adjacent electrodes adjacent to said one of the touch sensing electrodes is sensed to determine a force of the touch on the touch panel, and in the second sensing mode, the second touch sense signal from said one of the touch sensing electrodes but excluding the adjacent electrodes adjacent to said one of the touch sensing electrodes is sensed to determine a location of the touch on the touch panel.
 7. The touch panel of claim 6, wherein in the first sensing mode, the one or more adjacent electrodes are electrically coupled to said one of the touch sensing electrodes, and wherein in the second sensing mode, the one or more adjacent electrodes are electrically decoupled from said one of the touch sensing electrodes.
 8. The touch panel of claim 7, wherein in the second sensing mode the one or more adjacent electrodes are in an electrically floating state.
 9. The touch panel of claim 4, wherein the adjacent electrodes include first adjacent electrodes and second adjacent electrodes, each of the touch sensing electrodes disposed between one of the first adjacent electrodes and one of the second adjacent electrodes.
 10. The touch panel of claim 9, wherein said one of the first adjacent electrodes and said one of the second adjacent electrodes are physically connected to each other.
 11. The touch panel of claim 10, further comprising first routing lines and second routing lines, each of the first routing lines connected to corresponding one of the touch sensing electrodes and each of the second routing lines connected to corresponding one of the first adjacent electrodes.
 12. The touch panel of claim 6, wherein responsive to determining the location of the touch in the second sensing mode, one or more selected electrodes from the first electrodes corresponding to the location of the touch are applied with the touch driving pulse to determine the force of the touch individually one at a time.
 13. The touch panel of claim 6, wherein responsive to failing to determine the location of the touch in the second sensing mode, a group of electrodes from the first electrodes are applied with the touch driving pulse to determine the force of the touch simultaneously.
 14. The touch panel of claim 13, wherein: responsive to determining the force of the touch through the group of electrodes, one or more selected electrodes from the group of electrodes are applied with the touch driving pulse to determine the location and the force of the touch individually one at a time, and responsive to failing to determine the force of the touch through the group of electrodes, the first electrodes are applied with the touch driving pulse to determine the location of the touch in the second sensing mode.
 15. A method of operating a touch panel including first electrodes and second electrodes separated from and intersecting the first electrodes, the method comprising: applying a touch driving pulse to the first electrodes during a first sensing mode and a second sensing mode; sensing a first touch sense signal responsive to the touch driving pulse in the first sensing mode through the second electrodes; and sensing a second touch sense signal responsive to the touch driving pulse in the second sensing mode through a subset of the second electrodes.
 16. The method of claim 15, wherein: in the first sensing mode, the first touch sense signal is sensed based at least in part on a first capacitance between the first electrodes and the second electrodes responsive to the touch driving pulse, and in the second sensing mode, the second touch sense signal is sensed based at least in part on a second capacitance between the first electrodes and the subset of the second electrodes responsive to the touch driving pulse, the second capacitance less than the first capacitance.
 17. The method of claim 15, wherein the second electrodes include touch sensing electrodes and adjacent electrodes adjacent to the touch sensing electrodes, and wherein the subset of the second electrodes includes the touch sensing electrodes but excludes the adjacent electrodes.
 18. The method of claim 17, further comprising: in the first sensing mode determining a force of the touch on the touch panel based on the first touch sense signal sensed from at least one of the touch sensing electrodes and one or more of the adjacent electrodes adjacent to said one of the touch sensing electrodes; and in the second sensing mode determining a location of the touch on the touch panel based on the second touch sense signal sensed from said one of the touch sensing electrodes but excluding the adjacent electrodes adjacent to said one of the touch sensing electrodes.
 19. The method of claim 18, further comprising: electrically coupling, in the first sensing mode, the one or more adjacent electrodes to said one of the touch sensing electrodes; and electrically decoupling, in the second sensing mode, the one or more adjacent electrodes from said one of the touch sensing electrodes.
 20. The method of claim 19, further comprising placing, in the second sensing mode, the one or more adjacent electrodes in an electrically floating state.
 21. The method of claim 18, further comprising: responsive to determining the location of the touch in the second sensing mode, applying the touch driving pulse to one or more electrodes from the first electrodes corresponding to the location of the touch to determine force of the touch individually one at a time.
 22. The method of claim 18, further comprising: responsive to failing to determine the location of the touch in the second sensing mode, applying the touch driving pulse to a group of electrodes from the first electrodes to determine force of the touch simultaneously.
 23. The method of claim 22, further comprising: responsive to determining the force of the touch through the group of electrodes, selecting one or more electrodes from the group of electrodes and applying the touch driving pulse to the one or more selected electrodes to determine the location and the force of the touch individually one at a time; and responsive to failing to determine the force of the touch through the group of electrodes, applying the touch driving pulse to the first electrodes in the second sensing mode to determine the location of the touch. 